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Mirrors > Home > MPE Home > Th. List > finlocfin | Structured version Visualization version GIF version |
Description: A finite cover of a topological space is a locally finite cover. (Contributed by Jeff Hankins, 21-Jan-2010.) |
Ref | Expression |
---|---|
finlocfin.1 | ⊢ 𝑋 = ∪ 𝐽 |
finlocfin.2 | ⊢ 𝑌 = ∪ 𝐴 |
Ref | Expression |
---|---|
finlocfin | ⊢ ((𝐽 ∈ Top ∧ 𝐴 ∈ Fin ∧ 𝑋 = 𝑌) → 𝐴 ∈ (LocFin‘𝐽)) |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | simp1 1116 | . 2 ⊢ ((𝐽 ∈ Top ∧ 𝐴 ∈ Fin ∧ 𝑋 = 𝑌) → 𝐽 ∈ Top) | |
2 | simp3 1118 | . 2 ⊢ ((𝐽 ∈ Top ∧ 𝐴 ∈ Fin ∧ 𝑋 = 𝑌) → 𝑋 = 𝑌) | |
3 | simpl1 1171 | . . . . 5 ⊢ (((𝐽 ∈ Top ∧ 𝐴 ∈ Fin ∧ 𝑋 = 𝑌) ∧ 𝑥 ∈ 𝑋) → 𝐽 ∈ Top) | |
4 | finlocfin.1 | . . . . . 6 ⊢ 𝑋 = ∪ 𝐽 | |
5 | 4 | topopn 21208 | . . . . 5 ⊢ (𝐽 ∈ Top → 𝑋 ∈ 𝐽) |
6 | 3, 5 | syl 17 | . . . 4 ⊢ (((𝐽 ∈ Top ∧ 𝐴 ∈ Fin ∧ 𝑋 = 𝑌) ∧ 𝑥 ∈ 𝑋) → 𝑋 ∈ 𝐽) |
7 | simpr 477 | . . . 4 ⊢ (((𝐽 ∈ Top ∧ 𝐴 ∈ Fin ∧ 𝑋 = 𝑌) ∧ 𝑥 ∈ 𝑋) → 𝑥 ∈ 𝑋) | |
8 | simpl2 1172 | . . . . 5 ⊢ (((𝐽 ∈ Top ∧ 𝐴 ∈ Fin ∧ 𝑋 = 𝑌) ∧ 𝑥 ∈ 𝑋) → 𝐴 ∈ Fin) | |
9 | ssrab2 3942 | . . . . 5 ⊢ {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑋) ≠ ∅} ⊆ 𝐴 | |
10 | ssfi 8525 | . . . . 5 ⊢ ((𝐴 ∈ Fin ∧ {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑋) ≠ ∅} ⊆ 𝐴) → {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑋) ≠ ∅} ∈ Fin) | |
11 | 8, 9, 10 | sylancl 577 | . . . 4 ⊢ (((𝐽 ∈ Top ∧ 𝐴 ∈ Fin ∧ 𝑋 = 𝑌) ∧ 𝑥 ∈ 𝑋) → {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑋) ≠ ∅} ∈ Fin) |
12 | eleq2 2848 | . . . . . 6 ⊢ (𝑛 = 𝑋 → (𝑥 ∈ 𝑛 ↔ 𝑥 ∈ 𝑋)) | |
13 | ineq2 4065 | . . . . . . . . 9 ⊢ (𝑛 = 𝑋 → (𝑠 ∩ 𝑛) = (𝑠 ∩ 𝑋)) | |
14 | 13 | neeq1d 3020 | . . . . . . . 8 ⊢ (𝑛 = 𝑋 → ((𝑠 ∩ 𝑛) ≠ ∅ ↔ (𝑠 ∩ 𝑋) ≠ ∅)) |
15 | 14 | rabbidv 3397 | . . . . . . 7 ⊢ (𝑛 = 𝑋 → {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑛) ≠ ∅} = {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑋) ≠ ∅}) |
16 | 15 | eleq1d 2844 | . . . . . 6 ⊢ (𝑛 = 𝑋 → ({𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑛) ≠ ∅} ∈ Fin ↔ {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑋) ≠ ∅} ∈ Fin)) |
17 | 12, 16 | anbi12d 621 | . . . . 5 ⊢ (𝑛 = 𝑋 → ((𝑥 ∈ 𝑛 ∧ {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑛) ≠ ∅} ∈ Fin) ↔ (𝑥 ∈ 𝑋 ∧ {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑋) ≠ ∅} ∈ Fin))) |
18 | 17 | rspcev 3529 | . . . 4 ⊢ ((𝑋 ∈ 𝐽 ∧ (𝑥 ∈ 𝑋 ∧ {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑋) ≠ ∅} ∈ Fin)) → ∃𝑛 ∈ 𝐽 (𝑥 ∈ 𝑛 ∧ {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑛) ≠ ∅} ∈ Fin)) |
19 | 6, 7, 11, 18 | syl12anc 824 | . . 3 ⊢ (((𝐽 ∈ Top ∧ 𝐴 ∈ Fin ∧ 𝑋 = 𝑌) ∧ 𝑥 ∈ 𝑋) → ∃𝑛 ∈ 𝐽 (𝑥 ∈ 𝑛 ∧ {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑛) ≠ ∅} ∈ Fin)) |
20 | 19 | ralrimiva 3126 | . 2 ⊢ ((𝐽 ∈ Top ∧ 𝐴 ∈ Fin ∧ 𝑋 = 𝑌) → ∀𝑥 ∈ 𝑋 ∃𝑛 ∈ 𝐽 (𝑥 ∈ 𝑛 ∧ {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑛) ≠ ∅} ∈ Fin)) |
21 | finlocfin.2 | . . 3 ⊢ 𝑌 = ∪ 𝐴 | |
22 | 4, 21 | islocfin 21819 | . 2 ⊢ (𝐴 ∈ (LocFin‘𝐽) ↔ (𝐽 ∈ Top ∧ 𝑋 = 𝑌 ∧ ∀𝑥 ∈ 𝑋 ∃𝑛 ∈ 𝐽 (𝑥 ∈ 𝑛 ∧ {𝑠 ∈ 𝐴 ∣ (𝑠 ∩ 𝑛) ≠ ∅} ∈ Fin))) |
23 | 1, 2, 20, 22 | syl3anbrc 1323 | 1 ⊢ ((𝐽 ∈ Top ∧ 𝐴 ∈ Fin ∧ 𝑋 = 𝑌) → 𝐴 ∈ (LocFin‘𝐽)) |
Colors of variables: wff setvar class |
Syntax hints: → wi 4 ∧ wa 387 ∧ w3a 1068 = wceq 1507 ∈ wcel 2048 ≠ wne 2961 ∀wral 3082 ∃wrex 3083 {crab 3086 ∩ cin 3824 ⊆ wss 3825 ∅c0 4173 ∪ cuni 4706 ‘cfv 6182 Fincfn 8298 Topctop 21195 LocFinclocfin 21806 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1758 ax-4 1772 ax-5 1869 ax-6 1928 ax-7 1964 ax-8 2050 ax-9 2057 ax-10 2077 ax-11 2091 ax-12 2104 ax-13 2299 ax-ext 2745 ax-sep 5054 ax-nul 5061 ax-pow 5113 ax-pr 5180 ax-un 7273 |
This theorem depends on definitions: df-bi 199 df-an 388 df-or 834 df-3or 1069 df-3an 1070 df-tru 1510 df-ex 1743 df-nf 1747 df-sb 2014 df-mo 2544 df-eu 2580 df-clab 2754 df-cleq 2765 df-clel 2840 df-nfc 2912 df-ne 2962 df-ral 3087 df-rex 3088 df-rab 3091 df-v 3411 df-sbc 3678 df-dif 3828 df-un 3830 df-in 3832 df-ss 3839 df-pss 3841 df-nul 4174 df-if 4345 df-pw 4418 df-sn 4436 df-pr 4438 df-tp 4440 df-op 4442 df-uni 4707 df-br 4924 df-opab 4986 df-mpt 5003 df-tr 5025 df-id 5305 df-eprel 5310 df-po 5319 df-so 5320 df-fr 5359 df-we 5361 df-xp 5406 df-rel 5407 df-cnv 5408 df-co 5409 df-dm 5410 df-rn 5411 df-res 5412 df-ima 5413 df-ord 6026 df-on 6027 df-lim 6028 df-suc 6029 df-iota 6146 df-fun 6184 df-fn 6185 df-f 6186 df-f1 6187 df-fo 6188 df-f1o 6189 df-fv 6190 df-om 7391 df-er 8081 df-en 8299 df-fin 8302 df-top 21196 df-locfin 21809 |
This theorem is referenced by: locfincmp 21828 cmppcmp 30723 |
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